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Purpose.To compare the morphology of the distal femur between Caucasian and Japanese women. Methods. 30 Caucasian women aged 41 to 84 (mean, 67) years and 70 Japanese women aged 54 to 86 (mean, 70) years who underwent total knee arthroplasty for osteoarthritis were randomly selected. Morphologic measurements of the distal femur were compared using lateral radiographs. Both race and height influenced the morphology. To adjust for the influence of height on morphology, each measurement was divided by the patient's height and the ratios were compared. Results. Caucasian women were generally taller and heavier (p<0.001) and had higher body mass index (p=0.03) than the Japanese women. Each morphologic measurement of the distal femur was significantly longer in the Caucasian women. In both groups, anteroposterior width of the condyle correlated more with height than weight. In women of equal height, the anteroposterior and metaphyseal widths of the femur and the anterior and resected condyles were

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Parathyroid hormone-related peptide (PTHrP) and insulin-like growth factor I (IGF-I) are both involved in the regulation of bone and cartilage metabolisms and their interaction has been reported in osteoblasts. To investigate the interaction of PTHrP and IGF-I during fracture healing, the expression of mRNA for PTHrP and IGF-I, and receptors for PTHlPTHrP and IGF were examined during rat femoral fracture healing using an in situ hybridization method and an immunohistochemistry method, respectively. During intramembranous ossification, PTHrP mRNA, IGF-I mRNA and IGF receptors were detected in preosteoblasts, differentiated osteoblasts and osteocytes in the newly formed trabecular bone. PTHlPTHrP receptors were markedly detected in osteoblasts and osteocytes, but only barely so in preosteoblasts. During cartilaginous callus formation, PTHrP mRNA was expressed by mesenchymal cells and proliferating chondrocytes. PTHlPTHrP receptors were detected in proliferating chondrocytes and early hypertrophic chondrocytes. IGF-I mRNA and IGF receptor were co-expressed by mesenchymal cells, proliferating chondrocytes, and early hypertrophic chondrocytes. At the endochondral ossification front, osteoblasts were positive for PTHrP and IGF-I mRNA as well as their receptors. These results suggest that IGF-I is involved in cell proliferation or differentiation in mesenchymal cells, periosteal cells, osteoblasts and chondrocytes in an autocrine andlor paracrine fashion. Furthermore, PTHrP may be involved in primary callus formation presumably co-operating with IGF-I in osteoblasts and osteocytes, and by regulating chondrocyte differentiation in endochondral ossification. IntroductionDuring fracture healing, several cellular events occur simultaneously and/or sequentially: inflammatory reaction, chondrogenesis, intramembranous ossification and endochondral ossification, resulting in the formation of a fracture callus followed by bony union. These dynamic events of bone metabolism are biologically regulated and can be investigated representatively in animal fracture models [15]. It has been reported that various local regulators such as cytokines and growth factors are expressed during fracture healing suggesting they regulate proliferation and/or differentiation of cells involved in fracture healing [11,39]. Since many growth factors regulate biological reaction of cells in co-operation with other factors or modulate the function of other factors [9,10,36], these interaction between different local regulators may be important for the well-organized repair process of fracture healing.Parathyroid hormone-related peptide (PTHrP) was originally isolated from tumors associated with humoral hypercalcemia of malignancy [34]. It has been reported that PTHrP is expressed in a wide variety of fetal and neonatal tissues [8,37], and acts in an autocrine/paracrine fashion binding with the same receptor as parathyroid hormone (PTH) does [16]. During embryonal cartilage development, PTHrP is expressed in the perichondrium induced by Indian ...